Ignition test device



Sept. 3, 1940. G. ZITZMANN 2,213,297.

IGNITION TEST DEVICE Filed April 29, 1939 Patented Sept. 3, 1940 UNITED STATES PATENT FFICE Application April 29,

6 Claims.

This invention relates to improvements in test devices, and more particularly to improvements in devices for testing the ignition systems of internal combustion engines.

An object of the present invention is to provide a new, simple, and efficient device capable of being used to test ignition systems.

Another object of the invention is to provide a device in which the operating parts thereof are incorporated in the handle of a conventional tool.

A further object of the invention is to provid a testing device having electrodes relatively separable, together with combined means for separ. rating the electrodes and for indicating the def gree of separation thereof.

A still further object of the invention is to provide a testing device of the foregoing character in which provision is made for readily sevg curing a conductor to the device and for removing the same therefrom. 3

In carrying out the foregoing and other ob jects of the invention, a device incorporating the same is made up substantially in the form of a screw driver having a blade and a handle therefor. The blade serves as one terminal for the device, having an electrode secured to the inner end thereof within the handle. A second electrode secured to a rack member is slidably 30 mounted within the handle so that the distance between the electrodes can be varied. Electrical connection to the second electrode is provided through a terminal member within the handle for attachment to a terminal on the end of a cable or other conductor. For imparting reciprocation to the movable electrode, use is made of a rotary member having teeth in the periphery thereof to engage with the rack, whereby rotation of this member causes reciprocation of the rack. A part of this rotary member extends beyond the surface of the handle, and the visible part is provided with legendary matter whereby the distance between the electrodes can be determined readily. Windows are provided in the handle so that the ends of the electrodes can be visible, and the electrodes are surrounded by some transparent shielding member whereby an are between the electrodes will be visible, yet inclosed.

Other features, objects, and advantages of the invention will become apparent by reference to the following detailed description of the accompanying drawing, wherein;

Fig. 1 is a view of the device embodying the invention;

Fig. 2 is an enlarged vertical section of the handle portion of the device, and a Fig. 3 is a section taken substantially on the line 3-3 of Fig. 1.

Referring now to the drawing, l 0 indicates gen- 1939, Serial No. 270,803

erally the handle of the device, which handle is made substantially in the form of a conventional screw driver handle. Secured in one end of the handle i0 is a screw driver blade H fastened thereto by a pin l2 passing through a ferrule 14 or in any other suitable manner. The handle 10, as shown in Fig. 2, has a bore l5 which extends from the top of the handle to the hollowed out part thereof receiving the end of the blade I I. An electrode I6 is secured in the inner end of the blade H and this electrode may be made of any suitable material, such as nickel, or any other metal which does not easily deteriorate due to the action of arcs. Within the bore l5 and adjacent the end of blade 1! is a tubular sleeve 1-! of glass or any other suitable transparent material. Immediately above this sleeve I1 is a second sleeve l8 of fibre or any other suitable insulating material. A leaf spring I9 has one end thereof secured to the sleeve l8 by a rivet 20.

A rack member 2i has a channel 22 cut in the surface therof and extending longitudinally the full length thereof. This channel is of a width suflicient to receive the flat leaf spring l9, as shown clearly in Fig. 3. The rack 2| is provided with teeth 2i positioned substantially diametrically opposite the channel 22. To one end of the rack 2i is secured an electrode 25 of material similar to the electrode I 6.

In order that this rack and its attached electrode 25 can be reciprocated in the handle, the handle is provided with a through opening 26 in which is rotatably mounted a wheel 21 of fibre or some other suitable insulating material. A pin 28 is used to afford this pivotal mounting of the wheel. A part of the periphery of wheel 21 has teeth 29 cut therein while the remainder of the periphery of the wheel is knurled or otherwise roughened as at 30 to provide such a surface as will permit the wheel to be rotated by manual operation. The knurled part, as shown in Fig. 2, extends beyond the surface of the handle so that it is readily convenient to the finger of an operator, as the result of which the wheel can be rotated and thereby the rack 2i and its attached electrode 25 are reciprocated. A plurality of legendary numerals 3! are imprinted or otherwise formed on one surface of the wheel 21 in arcuate fashion, so that certain of the numbers are always visible. The purpose of these numbers will be explained later.

In order that electrical connection can be made between the electrode 25 and a conductor 35 in a cable 36, this cable 36 has a thimble-like member 3! secured to one end thereof and electrically fastened to one end of the conductor 35. The walls of the thimble-like member 31 aresplit and this thiinble is of such resilient metal that the split portions are normally forced outwardly. However, the thimble can be compossible use thereof as an ordinary tool.

pressed by inserting the same in the bore 15, and such insertion can be accomplished until the end of the thimble contacts with a button member 38 mounted in the bore H3. The under side of button 38 has one end of a coiled spring 38 secured thereto, while the other end of the coiled spring rests on the end of the insulating sleeve l8. An electrical connection in the nature of a flexible strap is provided between thespring. 39 and the' upper end of leaf spring l9. Due to this arrangement it is evident that a circuit can be traced from a spring clip 42 on the free end of the cable 35 through the conductor 35 to the thimble 31-, thence to the button 38 through spring 39 to spring l9, from the spring l9 through the rack 21 to the electrode 25. Due to the provision of the button 38 and the spring 39, together with the spring thirnble 31, a good electrical connection from the conductor in the cable to the movable electrode is assured.

In order that the ends of the electrodes 26 and 25 can be visible along with any arc therebetween, oppositely disposed windows 45 are cut in the handle and these recesses or windows are of such length that the electrodes will be visible through the glass sleeve H in practically all their adjusted positions.

The device is capable of being used for testing ignition systems in the usual manner, that is, by connecting the spring clip 42 to a suitable part of the system and then by grounding the screw driver blade H to the engine or to any other suitable point. The flow of current can be checked by determining the relative distance between the electrodes l6 and 25, and adjustment can be made to cause these electrodes to be at such dis-' arise as to permit an arc to pass therebetween. The numerals 3| on the wheel 21 are utilized for indicating visually to an operator the distance between the electrodes, it being understood that the numeral closest to a horizontal position relative to the handle will indicate this distance.

From the foregoing it will be seen that the present invention provides a new, simplified, ig-

, nition testing device capable of performing the usual functions of such a device, and which is at the same time capable of being used as a tool for other purposes when so desired. The ready detachability of the cable 35 from the device makes The arrangement of the rotary wheel for reciprocating the movable electrode combines the function of such reciprocation, together with position indication.

It will be apparent that the device is capable of modification beyond the illustrated embodiment, in view of which any limitations imposed thereupon are to be only those set forth in the following claims.

What I claim is:

l. A test device comprising a hollowed out handle member, a terminal secured in one end of said member and extending axially therefrom and having an electrode attached thereto and positioned in said handle, a slidably mounted electrode carrier within said handle and havin an electrode secured to one end thereof, means mounted in said handle and extending partially outside thereof for moving said carrier and associated electrode to vary the distance between said electrodes, and a quickly removable flexible electric conductor secured in the other end of said handle, said conductor being connectable electrically to said electrode carrier.

2. A test device comprising a hollowed out handle member, a terminal secured in one end of said member and extending axially therefrom and having an electrode attached thereto and positioned in said handle, a slidably mounted electrode carrier within said handle and having an electrode secured to one end thereof, means mounted in said handle and extending partially outside thereof for moving said carrier and associated electrode to vary the gap between said electrodes, the part of said means extending outside said handle having indicia thereon for indicating the length of said gap, and a quickly removable flexible electric conductor secured in the other end of said handle, said conductor being connectable electrically to said electrode carrier.

3. A test device comprising a. hollowed out handle, a terminal member secured in one end thereof and extending axially therefrom and having an electrode attached thereto and positioned in said handle, a reciprocable member mounted in said handle and having an electrode secured to one end thereof, means located partially within said handle and partically outside thereof for reciprocating said member axially of said handle, and means for removably attaching a conductor to the other end of said handle, and means for I" establishing an electric path from said conductor to said movable electrode.

4. A test device comprising a hollowed out handle, a terminal member secured in one end thereof and extending axially therefrom and having an electrode attached thereto and positioned in said handle, a reciprocable member mounted in said handle and having an electrode secured to one end thereof, means located partially within said handle and partially outside thereof for reciprocating said member axially of said handle, and a. transparent shield surrounding said electrodes, said handle having a window therein whereby said electrodes are visible through said shield.

5. A test device comprising a handle member having a longitudinal axial bore, a terminal secured in one end of said member and having an electrode attached thereto and positioned in said handle, a slidably mounted electrode carrier within said handle and havir1 an electrode secured to one end thereof, means mounted in said handle and extending partially outside thereof for moving said carrier and associated electrode axially of the handle, a conductor having a recured to one end thereof, and a rotary member pivoted in said handle, said rotary member having teeth engaging said rack member and having a part thereof extending beyond the well of said handle for manipulation of said rotary member to reciprocate said rack axially of the handle. GEORGE ZI'IZMANN. 

